"DAB sounds worse than FM" wrote in message
...
Keith G wrote:
"DAB sounds worse than FM" wrote in message
...
David Looser wrote:
"DAB sounds worse than FM" wrote

. For example, the latest digital mobile broadcasting systems are 10
times as efficient as DAB.

What is that supposed to mean? What sort of "efficiency" are you
talking about? Spectral efficiency?, capital cost efficiency?, power
efficiency?, what?


DVB-T2 is 10.5 times as efficient as DAB in terms of the number of
stations that can be carried at a certain level of audio quality per MHz
of spectrum. Spectral efficiency isn't the appropriate parameter to use
to compare digital radio systems because it ignores the efficiency of
the
audio codec. The above figure combines the spectral and audio coding
efficiencies.

Capital cost efficiency and power efficiency are equal to the efficiency
figure (10.5) given above, because DAB and DVB-T2 are compared on the
basis of them using the same required C/N ratio, which implies that the
multiplex transmission power will be the same when they use the same
channel bandwidth, and DAB and DVB-T2 are specified to use the same 1.7
MHz bandwidth Band III channels. As the transmission powers are the same
for both systems, the power efficiency is simply the power divided by
the
number of stations, which in relative terms is precisely equal to the
efficiency value given above. Similarly, the capital cost efficiency is
also simply the multiplex capital cost divided by the number of
stations,
which again in relative terms is equal to the efficiency value given
above.

DVB-T2 is also 3.5 times as efficient as DAB+ - that's purely down to
spectral efficiency, because they both use the same AAC/AAC+ audio
codec.


Come to that what do you mean by "mobile broadcasting systems"?


Substitute "broadcasting" for "phone" in the term "mobile phone system"
and hopefully you get the picture. Stationary reception is basically a
special case of mobile reception just at 0 mph.

Basically, mobile broadcasting systems have been specifically designed
to
allow for reception on mobile devices - not all broadcasting systems
have
been designed to allow mobile reception, for instance DVB-T whcih is
used
for Freeview in the UK didn't include any technologies to make it
suitable for mobile reception - and mobile reception of Freeview
channels would be hopeless in the UK especially because of the
transmission parameters used (2K subcarriers, 7us guard interval
duration). I look forward to a deep and meaningful discussion of all
things mobile
comms with you, David. Or should I say DAB Fanboy 3, IIRC?



DAB Fanboy 3 now?

(That'll be the whole of the UK by Christmas, at this rate!)

You just don't know when to stop digging, do you?


Hahahahahahahahhahahahahahaha!!!! Don't know when to stop digging? WTF are
you on about?



Oops!

Good job I'm not a dentist, ain't it?

:-)